It is generally accepted that some form of counselling is essential after someone has experienced a traumatic event.

But a study published in the Journal of the Royal Society of Medicine suggests that current techniques are "inadequate" and that in some cases they can be harmful because they summon up distressing memories.

Post-traumatic stress disorder can occur after a severely disturbing event such as being raped or robbed, or after exposure to a highly stressful environment, such as a war zone.

It is a disturbing psychological condition where people relive painful memories against their will. This leads to feelings of isolation and a sense of losing control.

Prevention rather than cure

A form of counselling known as psychological debriefing is often offered to prevent the condition in soldiers after a tour of duty or in bank employees after an armed raid.

The new study says that better treatment is required.

Dr Martin Deahl, a consultant at St Bartholomew's Hospital, London, and a member of the Territorial Army, studied the effectiveness of psychological debriefings of soldiers who had served in the 1991 Gulf war.

His team followed the progress of two groups of soldiers - those who had received psychological debriefing and those who had not.

They found that outcomes were the same for both groups and concluded that psychological debriefing offers "no clear benefit" in preventing post-traumatic stress disorder in soldiers.

Personal experience

Dr Deahl first got interested in the syndrome after he attended victims at the Kings Cross underground fire in London. At the time, he was a trainee at the Institute of psychiatry.

He was the first doctor on the scene, and had to handle and identify dead bodies.

"When I went to work the following morning, the great and the good of psychiatry, when they found out what I had done, got the chaplain to come and talk to me," he said.

"I was astonished that they should react like that and that they felt somethoing should be done - that is how I got interested in the field."

Regular distress

Post-traumatic stress disorder is most likely to affect people in jobs that expose them to distressing events on a regular basis.

Emergency service workers are exposed to distressing scenes

The study says that up to 30% of workers in the emergency services will report symptoms within a year of experiencing trauma.

Those in the armed forces are, however, at highest risk - hence the syndrome's alternative name, shell shock.

The study says that among veterans of the 1982 Falklands War, incidence was as high as 50%, and it was 54% among survivors of the Gulf War "friendly fire" incident, where soldiers were attacked by their own side.

"Serious psychological distress" has also been reported among support workers such as control room workers and administrative staff, the study said.

It proposes that counselling techniques after the event should only be part of the preventive treatment for the disorder.

Extra measures

Counselling should be supported by preparatory training for stressful events, it says, and measures should include:

"Stress inoculation" - where trainee doctors, nurses and soldiers get used to handling human remains;

"Educational briefings" - where those at risk are told what the effects of trauma are likely to be and what steps they can take to regain a sense of control;